"People were getting confused by the need to install a project called IPython to provide a UI for writing code in Julia or R," said Min Ragan-Kelley, core developer of both IPython and Jupyter. "[So] now, they install Jupyter, which is a name less tied to any particular language."

The most visible piece of Jupyter is the notebook interface, which is commonly used to work with Python via IPython. Now it can interoperate with a few dozen other languages, including Julia, R, Scala, JavaScript, Matlab, and Bash. "What used to be a monolithic IPython package is now several packages containing the different pieces, such as the notebook, qtconsole, notebook format, nbconvert utility, parallel Python library, etc.," Ragan-Kelley said.

In addition to removing the confusion of having a multilanguage tool called IPython, the separation of the various IPython components into separate Jupyter components "will allow the different components to be developed and released at their own pace, hopefully enabling quicker responses to user needs," Ragan-Kelley said.

Users who still want everything can get a Jupyter meta-package that has all the pieces, Kelley said. The software features an interactive shell, the REPL protocol, a notebook document format, and tools for building widgets.